JP2015086927A - Check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a back-flow caused by poor operation of a valve body of a check valve due to adhesion of dust and scale.SOLUTION: This invention relates to a check valve characterized in that it comprises a valve seat arranged at a horizontal wall part of a casing and having a flow passage at its central part in a vertical direction; a valve body liquid tightly and closely contacted with the valve seat within the casing; one of outer cylinder and an inner cylinder extending in a vertical direction within the casing to support the valve body; the other cylinder of the outer cylinder and the inner cylinder fixed in the casing, extending in a vertical direction and slidably contacted with the one cylinder to guide an ascending or descending motion of the one cylinder; a resilient member arranged in the inner cylinder to always bias the valve body toward the valve seat; a flat and smooth low adhering material defining at least a part of full length of an outer circumferential surface of the inner cylinder and slidably contacted with the outer cylinder; a flowing-in passage arranged at a side opposite to the side where the valve body is arranged in respect to the horizontal wall; and a flowing-out passage arranged in the casing at a side where the valve body is arranged in respect to the horizontal wall part.

Description

  The present invention relates to a check valve that can be used for piping for supplying dust-removed water containing dust and scales by sprinkling water to blast furnace gas discharged from a blast furnace or sprinkling cooling water in a continuous casting line. The present invention relates to a check valve that prevents malfunction due to scale sticking.

  When supplying the blast furnace gas discharged from the blast furnace to the turbine of the blast furnace top pressure power generator, the blast furnace gas is passed through the wet dust collector and then sprinkled on the blast furnace gas to reduce dust, so dust removal from the wet dust collector Water and dust removal water sprinkled by blast furnace gas after that contain a large amount of dust.

  Also, when casting a slab from molten steel in a continuous casting line, dust is sprayed on the slab in order to cool the slab and remove the scale on the slab surface. Contains a large amount of scale.

  Such dust removal water is separated into dust and scale in a thickener (coagulation sedimentation tank), dust and scale are used as resources after being compressed and degreased, and dust removal water is reused for dust removal of blast furnace gas and slab. Is done.

  By the way, in a system that circulates dust removal water in a blast furnace or continuous casting line, in order to use a large amount of dust removal water, dust removal water may be sent from multiple pumps to a common water supply pipe. A check valve is provided between the outlet of each pump and the common water supply pipe so that the dust-removed water does not flow backward from the common water supply pipe to the pump side during the stoppage of the pump.

  A conventional check valve in a system that circulates dust-removed water in a blast furnace or continuous casting line delivers a large amount of dust-removed water as described above. Therefore, a disc-shaped valve element whose center is bent by a hinge is a circular valve. A duo type that is pivotally supported downstream of the seat and urged by a spring in a direction in which the valve body returns to a disk shape is mainly used.

  However, with this duo check valve, dust and scale adhere to the hinge and spring while the valve body is bent and allowed to pass dust-free water, and the flow of dust-free water from the pump stops. However, there is a disadvantage that the valve body returns to a disk shape by a spring and cannot be brought into close contact with the valve seat, and therefore cannot function as a check valve.

  As a check valve for preventing a back flow of a slurry which is a suspension mixed with powder or the like as in the case of dust removal water, a check valve described in Patent Document 1 is known. A spherical valve body is mounted on an upwardly truncated cone-shaped valve seat having a directional inflow path, and the valve body is guided by a cylindrical guide member, and the valve body is placed on the guide member. The upper limit position is determined and a holding member with an outflow path in the vertical direction is arranged, and a solid content discharge path that can be opened and closed by a valve is provided in communication with the pocket around the valve seat. The solid content separated from the water is deposited in a pocket around the valve seat so that it can be discharged from the solid content discharge passage.

JP 2006-46409 A

  However, even if the check valve described in Patent Document 1 is used in place of the conventional duo check valve, the check valve has a structure in which the valve body rides on the valve seat with its own weight to close the valve. , Even if dust and scale adhere between the valve body and the guide member while the valve body is raised and allowing the dust-removing water to flow, the valve body is in close contact with the valve seat It may not function as a check valve, and even if a spring is inserted between the valve body and the holding member, the spring will also be exposed to dust-removing water. May stick to the valve body.

  Therefore, an object of the present invention is to provide a check valve that advantageously solves the problems of the prior art.

The check valve of the present invention that achieves the above-described object provides:
A valve seat provided on the horizontal wall of the casing and having a flow path in the vertical direction in the center;
A valve body in liquid tight contact with the valve seat in the casing;
One cylinder out of an outer cylinder and an inner cylinder, which extends in the vertical direction in the casing and supports the valve body,
The other cylinder out of the outer cylinder and the inner cylinder, which is fixed in the casing and extends in the vertical direction and slides in contact with the one cylinder and guides the up-and-down movement of the one cylinder.
An elastic member disposed inside the inner cylinder and constantly biasing the valve body toward the valve seat;
A low-adhesive material with a smooth surface that defines at least part of the overall length of the outer peripheral surface of the inner cylinder and is in sliding contact with the outer cylinder;
An inflow path provided on a side opposite to the side on which the valve body is disposed with respect to the horizontal wall portion;
An outflow passage provided in the casing on the side where the valve body is disposed with respect to the horizontal wall portion;
It is characterized by comprising.

  In the check valve of the present invention, it is preferable that the casing and the valve body are located above the horizontal wall portion. Further, it is preferable that a pointed lip portion projects along the inner cylinder at the tip of the outer cylinder. Furthermore, the low adhesion material is preferably ultra high molecular weight polyethylene. Furthermore, it is preferable that the surfaces of the valve seat and the valve body that are in close contact with each other have a truncated cone shape.

  In the check valve of the present invention, a valve body that is supported in one of the outer cylinder and the inner cylinder and extends in the vertical direction in the casing is fixed in the one cylinder and the casing. Since the up and down movement is guided by sliding contact with the other cylinder extending in the vertical direction, the water that has flowed from the pump to the inflow path is the central portion of the valve seat provided on the horizontal wall portion of the casing. When the valve body is pressed against an elastic member such as a spring that constantly urges the valve body toward the valve seat through the vertical flow path of the valve, the sliding is caused by sliding contact between the outer cylinder and the inner cylinder. Then, the valve body moves up and down so as to be separated from the valve seat while compressing the elastic member, thereby opening the flow passage in the center portion of the valve seat, so that the water sent to the inflow passage is It flows into the casing through the flow path in the center of the seat, and the casing on the side where the valve element is arranged with respect to the horizontal wall Flowing out provided the outflow channel.

  On the other hand, when the flow of water from the pump to the inflow passage stops, the urging force of the elastic member that constantly urges the valve body toward the valve seat overcomes the pressing force of the water, and the valve body is in close contact with the valve seat, Combined with the pressure of the water flowing into the casing from the outflow path, the upper and lower flow paths in the center of the valve seat are liquid-tightly sealed to prevent the backflow of water into the inflow path. Function.

  By the way, when the flowing water is dust removal water, it flows into the casing through the flow path in the central part of the valve seat from the inflow path by the operation of the pump, and the side on which the valve body is arranged with respect to the horizontal wall part While flowing out from the outflow passage provided in the casing, dust and scale in the dust removal water try to adhere to the surface of the structure exposed to the dust removal water inside the casing, but the inner cylinder located inside the casing A low-adhesion material with a smooth surface that defines at least a part of the entire length of the outer peripheral surface is difficult to adhere to dust and scale and has low sliding resistance, so it does not prevent relative sliding with the outer cylinder. In addition, since the compressed elastic member such as a spring is surrounded by the outer cylinder and the inner cylinder and is isolated from the dust-removing water, it is difficult for dust and scale to adhere to the elastic member.

  Therefore, according to the check valve of the present invention, when the flow of water from the pump to the inflow passage stops, the valve body urged by the extension of the elastic member under the guidance by the sliding contact between the outer cylinder and the inner cylinder is provided. Smooth movement and close contact with the valve seat, and the fluid passage in the vertical direction at the center of the valve seat is liquid-tightly sealed. be able to.

(A), (b) is the top view and sectional drawing which show one Example of the non-return valve of this invention. It is sectional drawing which expands and shows the principal part of the non-return valve of the said Example. It is a basic diagram which shows the structure of the blast furnace gas dust removal system of the blast furnace top pressure generator which applied the check valve of the said Example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 3 is a schematic diagram showing the configuration of the blast furnace gas dust removal system of the blast furnace top pressure power generation apparatus to which the check valve of the above embodiment is applied, and reference numeral 1 in the figure indicates the blast furnace.

  The high-temperature and high-pressure blast furnace gas discharged from the blast furnace 1 was sequentially passed through the coarse dust removing device 2 and the wet dust remover 3 to remove a substantial part of the large amount of dust contained in the blast furnace gas. Then, it is supplied to a turbine of a generator (not shown) through a blast furnace gas supply path 4 and is used for power generation.

  By the way, the coarse dust removing device 2 and the wet dust remover 3 are sequentially passed to remove a considerable part of the large amount of dust contained in the blast furnace gas, but are passed through the blast furnace gas supply path 4. Dust is still contained in the blast furnace gas, and if this dust adheres to the rotor blades or stationary blades in the turbine of the generator, the power generation efficiency is lowered. Therefore, in order to reduce the amount of dust adhering to the turbine, the blast furnace gas supply passage 4 is provided with a dust removal water sprinkling circuit for spraying the dust removal water evenly to the blast furnace gas.

  In the dust removal water sprinkling circuit in the wet dust remover 3 and the blast furnace gas supply path 4, the dust removal water directly supplied from the water reservoir 5 and pressurized by the pressurizing pump 6 is pumped through the water feed pipe 7, and wet dust removal. The dust removal water sprayed into the machine 3 and the blast furnace gas supply path 4 is combined with the dust contained in the blast furnace gas to become dust removal water containing slurry, and the dust removal water containing the slurry is directly from the wet dust removal machine 3. It is discharged to the return trough 9 and discharged from the lower drain of the blast furnace gas supply path 4 to the return trough 9 via a BF (blast furnace) sewage pit 8.

  The dust-removed water containing the slurry collected in the return trough 9 is separated into slurry and dust-removed water by a classifier 10 and a thickener (coagulation sedimentation tank) 11, and the slurry is sent to a regulating tank 13 by a pump 12. Further, it is sent to a compression dehydrator (not shown) by a pump 14 to be made into a cake by compression dehydration and reused as a resource. On the other hand, the dust-removed water discharged from the thickener (sedimentation tank) 11 is directly stored in the water reservoir 5.

  By the way, in order to supply a large amount of dust removing water from the direct water reservoir 5 to the wet dust removing machine 3 and the dust removing water sprinkling circuit in the blast furnace gas supply path 4, usually a plurality of pressure pumps 6 (two in the illustrated example) are arranged in parallel. Each pressurizing pump is provided so that dust-removed water does not flow backward from the common water supply pipe 7 to the side of the pressurizing pump 6 during the pause while some pressurization pumps 6 for inspection or the like are stopped. A check valve 15 is provided between the outlet 6 and the common water supply pipe 7.

  FIGS. 1A and 1B are a plan view and a cross-sectional view showing a check valve of the above embodiment applied as a check valve 15 to the blast furnace gas dust removal system of the blast furnace top pressure power generator described above, and FIG. 2 is an enlarged cross-sectional view showing a main part of the check valve of the embodiment, and the check valve of this embodiment includes a cylindrical casing 21 arranged with the vertical direction as the axial direction. The casing 21 has a horizontal wall portion 22 as a bottom portion at the lower end portion in the axial direction and a lid 23 detachably at the upper end portion in the axial direction.

  The horizontal wall portion 22 of the casing 21 is provided with a frustoconical valve seat 25 having a flow path 24 in the vertical direction at the center, and the valve 21 is located above the valve seat 25 in the casing 21. A conical valve body 26 that is liquid-tightly in contact with the seat 25, an outer cylinder 27 that extends in the vertical direction and has a lower end coupled to the valve body 26 to support the valve body 26, and a lid 23 An inner cylinder 28 is provided which is inserted and has an upper end fixed to the lid 23.

  The inner cylinder 28 has an inner cylinder main body 29, a stopper member 30 screwed to the lower end portion of the inner cylinder main body 29, and a stopper member 30 among the portions of the inner cylinder main body 29 located in the casing 21. It is made of a low-adhesive material that covers at least a part of the entire length in the axial direction of the outer peripheral surface of the inner cylinder 28 and covers most of the inner cylinder 28, for example, an ultrahigh molecular weight polyethylene having a molecular weight of 3.3 to 4.5 million. The cylindrical member 31 has a cylindrical member 31, which is in sliding contact with the outer cylinder 27 to guide the up-and-down movement of the outer cylinder 27 and can be exchanged by attaching and detaching the stopper member 30 when worn. .

  A spring seat 33 having a cylindrical spring holder 32 protruding from the center is fixed on the valve body 26 at a position inside the outer cylinder 27. On the spring seat 33, the valve body 26 is placed on the valve seat 26. A coil spring 34 as an elastic member that is always urged toward 25 is positioned by the spring holder 32 so as to be positioned inside the inner cylinder 28.

  A spring pressurizing shaft 36 having a hexagonal head at the upper end in the axial direction and an air hole 35 at the center is screwed inside the inner cylinder 28, and the upper and lower limits are indicated by phantom lines in the figure. By adjusting the screwing height of the spring pressurizing shaft 36 to the inner cylinder 28, the elastic force by which the coil spring 34 pressurizes the valve body 26 toward the valve seat 25 can be appropriately changed. A cap 37 having an air hole in the center is detachably provided at the upper end of the inner cylinder 28 fixed to the upper surface of the lid 23 to prevent unintentional rotation of the spring pressurizing shaft 36. It has been.

  Further, a sharp lip 38 is formed along the inner cylinder 28 at the upper end, which is the tip of the outer cylinder 27, and this lip 38 is formed on the surface of the cylindrical member 31 exposed in the casing 21. The adhering dust is scraped off as the outer cylinder 27 rises, and at the raised position of the outer cylinder 27, it is fluid-tightly fitted with a seal ring 39 provided on the lower surface of the lid body 23, Prevent intrusion of dust-removing water. A plurality of seal rings 40 are also provided on the inner peripheral surface of the outer cylinder 27 so as to be in sliding contact with the cylindrical member 31 and prevent entry of dust-removed water into the outer cylinder 27.

  Further, in the check valve of this embodiment, an inflow path 41 communicating with the flow path 24 is provided on the lower side, which is the side opposite to the side on which the valve body 26 is disposed, with respect to the horizontal wall portion 22. An outflow passage 42 communicating with the inside of the casing 21 is provided on the peripheral wall of the casing 21 located on the upper side, which is the side on which the valve body 26 is disposed with respect to the wall portion 22.

  In the check valve of this embodiment, a valve body 26 supported by an outer cylinder 27 extending in the vertical direction in the casing 21 is fixed to the outer cylinder 27 and the casing and extends in the vertical direction. Since the up-and-down movement is guided by the sliding contact with the existing inner cylinder 28, the dust-removed water that has flowed from the pressurizing pump 6 to the inflow passage 41 flows through the valve seat 25 provided on the horizontal wall portion 22 of the casing 21. When the valve body 26 is pressed against the coil spring 34 through the central flow path 24 in the vertical direction, the valve body 26 compresses the coil spring 34 under the guidance by sliding contact between the outer cylinder 27 and the inner cylinder 28. However, as indicated by the phantom line in FIG. 2, it moves upward away from the valve seat 25 to open the vertical flow path 24 at the center of the valve seat 25, thereby The dust-removed water that has been sent passes through the flow path 24 with an arrow in FIG. It flows into to as casing 21, and flows out from the outlet passage 42 provided in the casing 21.

  On the other hand, when the flow of the dust-removed water from the pressurizing pump 6 to the inflow passage 41 stops for inspection of the pressurizing pump 6 or the like, the coil spring 34 that constantly biases the valve body 26 toward the valve seat 25 is attached. The force exceeds the pressing force of the dust removal water from the inflow passage 41, and the valve body 26 comes into close contact with the valve seat 25, that is, sits on the valve seat 25 and combines with the pressure of the dust removal water flowing into the casing 21 from the outflow passage 42. The flow path 24 in the vertical direction at the center of the liquid is sealed in a liquid-tight manner to prevent the backflow of dust-removed water to the inflow path 41 and functions as a check valve.

  By the way, the dust-removed water that flows by the operation of the pressurizing pump 6 flows into the casing 21 from the inflow path 41 through the flow path 24 at the center of the valve seat 25 and is positioned above the horizontal wall section 22. While flowing out from the outflow passage 42 provided in the casing 21, dust in the dust removal water tends to adhere to the surface of the structure exposed to the dust removal water inside the casing 21. The cylindrical member 31 made of a low-adhesive material that defines most of the entire length of the outer peripheral surface of the inner cylinder 28 has a vertical surface and is difficult to adhere to dust. Since it is difficult to adhere and the sliding resistance is small, the relative sliding movement with the outer cylinder 27 is not hindered, and the compressed coil spring 34 is surrounded by the outer cylinder 27 and the inner cylinder 28 to remove dust. Isolated from the dust Fried, unimpeded extension by unloading.

  Therefore, according to the check valve of the present embodiment, when the flow of the dust removal water from the pressurizing pump 6 to the inflow passage 41 stops, the coil spring 34 is guided under the sliding contact between the outer cylinder 27 and the inner cylinder 28. The valve body 26 energized by the extension moves smoothly and comes into close contact with the valve seat 25, and the flow path 24 in the vertical direction at the center of the valve seat 25 is liquid-tightly sealed. Sometimes the backflow of the dust removal water can be reliably prevented.

  In addition, according to the check valve of the present embodiment, the casing 21 and the valve body 26 are located above the horizontal wall portion 22, so that the maintenance inside the casing 21 can be easily performed by removing the lid body 23. In addition, even when the urging force of the coil spring 34 decreases due to long-term use, the valve body 26 is urged toward the valve seat 25 by the water pressure from the outflow passage 42 to close the valve. , Backflow can be prevented.

  Further, according to the check valve of the present embodiment, the pointed lip portion 38 is projected along the inner cylinder 28 at the tip of the outer cylinder 27, so that the valve body 26 is seated on the valve seat 25. Even if dust adheres to the surface of the cylindrical member 31 exposed in the casing 21 after a long period of time in a state where dust-removed water is accumulated in the casing 21, the adhering dust is caused to rise as the outer cylinder 27 rises. Since the lip portion 38 is scraped off, the valve body 26 can be reliably moved up and down to open and close the valve.

  Furthermore, according to the check valve of the present embodiment, the low adhesion material forming the cylindrical member 31 is an ultra high molecular weight polyethylene having an extremely smooth surface, so that the dust adhesion preventing effect can be maintained over a long period of time. Can be obtained. Further, according to the check valve of the present embodiment, the surfaces of the valve seat 25 and the valve body 26 that are in close contact with each other have a truncated cone shape. Therefore, the urging force of the coil spring 34 is increased by the wedge effect to increase the valve force. The body 26 can be brought into close contact with the valve seat 25.

  When the check valve of this embodiment is applied to the check valve 15 of the blast furnace gas dust removal system of the blast furnace top pressure power generation apparatus described above, the check valve 15 does not operate at all for one year or more after the application. Not done. Therefore, the certainty of the operation of the check valve of this embodiment is clear.

  Although the present invention has been described based on the illustrated examples, the present invention is not limited to the above-described examples, and can be appropriately changed within the scope of the claims as required. For example, the casing 21 and the valve The body 26 may be positioned below the horizontal wall portion 22. Further, the valve body may be supported by the inner cylinder, the outer cylinder may be fixed to the casing, and the up-and-down movement of the inner cylinder may be guided by the outer cylinder. The low-adhesion material that defines at least a part of the outer peripheral surface of the inner cylinder may be Teflon (registered trademark) or a chromium-based metal, and instead of mounting the cylindrical member 31, the surface of the inner cylinder may be sprayed or plated. May be provided. Furthermore, although the check valve of the above embodiment is applied to the dust-removing water containing a lot of dust, it can also be applied to the dust-removing water containing a lot of scale.

  Thus, according to the check valve of the present invention, when the flow of water from the pump to the inflow passage is stopped, the valve body urged by the extension of the elastic member is smoothly guided by the sliding contact between the outer cylinder and the inner cylinder. To prevent the reverse flow when the pump is stopped, even when the pump is stopped. Can do.

DESCRIPTION OF SYMBOLS 1 Blast furnace 2 Coarse dust removal apparatus 3 Wet dust remover 4 Blast furnace gas supply path 5 Direct water reservoir 6 Pressurization pump 7 Water supply pipe 8 BF sewage pit 9 Return trough 10 Crash fire 11 Thickener 12, 14 Pump 13 Adjustment tank 15 Check valve DESCRIPTION OF SYMBOLS 21 Casing 22 Horizontal wall part 23 Cover body 24 Flow path 25 Valve seat 26 Valve body 27 Outer cylinder 28 Inner cylinder 29 Inner cylinder main body 30 Stopping member 31 Cylindrical member 32 Spring holder 33 Spring seat 34 Coil spring 35 Air hole 36 Spring supply Pressure shaft 37 Cap 38 Lip portion 39, 40 Seal ring 41 Inflow path 42 Outflow path

Claims (5)

A valve seat provided on the horizontal wall of the casing and having a flow path in the vertical direction in the center;
A valve body in liquid tight contact with the valve seat in the casing;
One cylinder out of an outer cylinder and an inner cylinder, which extends in the vertical direction in the casing and supports the valve body,
The other cylinder out of the outer cylinder and the inner cylinder, which is fixed in the casing and extends in the vertical direction and slides in contact with the one cylinder and guides the up-and-down movement of the one cylinder.
An elastic member disposed inside the inner cylinder and constantly biasing the valve body toward the valve seat;
A low-adhesive material with a smooth surface that defines at least part of the overall length of the outer peripheral surface of the inner cylinder and is in sliding contact with the outer cylinder;
An inflow path provided on a side opposite to the side on which the valve body is disposed with respect to the horizontal wall portion;
An outflow passage provided in the casing on the side where the valve body is disposed with respect to the horizontal wall portion;
A check valve characterized by comprising:   The check valve according to claim 1, wherein the casing and the valve body are located above the horizontal wall portion.   The check valve according to claim 1 or 2, wherein a pointed lip portion projects from the tip of the outer cylinder along the inner cylinder.   The check valve according to any one of claims 1 to 3, wherein the low adhesion material is ultra high molecular weight polyethylene.   The check valve according to any one of claims 1 to 4, wherein surfaces of the valve seat and the valve body that are in close contact with each other have a truncated cone shape.

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